1. Field of the Invention
This invention relates to a panel-mounted electrical connector having elastic locking arms on its outer periphery, and more particularly to such a connector wherein each locking arm flexes inwardly at an edge of a mounting hole formed in a panel when the connector is inserted into the mounting hole and each locking arm returns to its normal shape to engage the panel when the connector has been inserted into the hole to assume a normal position.
2. Description of the Prior Art
The electrical connector mentioned above includes those attached to panels composing a door or a body of an automobile so that electric parts equipped in the door are connected to the body side. FIG. 9 illustrates a conventional panel-mounted electrical connector 1. The connector 1 includes a front bottomed cylindrical hood 2. A plurality of male terminals 3 are held on a inner wall of the hood 2 so as to project toward its front open end. A flange 4 is formed on the outer periphery near the front end of the hood 2. When the connector 1 is inserted into a mounting hole W of a panel P, the flange 4 collides against panel P. A pair of slit-like notched portions are formed in each of upper and lower walls to extend from the open end toward the inner wall. Two locking arms 5 each formed into the shape of a plate with a small width and having elasticity are provided between the respective pairs of notched portions. Each locking arm 5 has a protrusion 6 formed on the outer peripheral side of its distal end. Each protrusion 6 has an inclined front side and a rear vertical end. A distance between the rear vertical wall surface and the front end wall surface of the flange 4 is so set as to be approximately equal to the thickness of the panel P.
When the above-described connector 1 is inserted into the mounting hole W of the panel P, the front end of each protrusion 6 collides against the edge of the panel P defining the hole W such that each locking arm 5 flexes inwardly. When the connector 1 is further inserted into the hole W such that the front wall surface of the flange 4 collides against the panel P, each protrusion 6 passes through the panel P, whereupon each locking arm 5 returns to its normal shape. The panel P is then held between the rear vertical wall surface of each protrusion 6 and the front wall surface of the flange 4, whereby the connector 1 is held on the panel P.
Since the male connectors 3 project in the hood 2, something can invade the hood 2 to strike against the male connectors 3 during transportation such that some or all the male connectors 3 bend. To prevent this, a protecting cap 7 (FIG. 10) is attached to the open end of the hood 2 to preliminarily close the end. The protecting cap 7 is inserted into the open end of the hood 2 so that the connector 1 with the cap 7 being attached thereto can be mounted on the panel P. Accordingly, the locking arms 5 are still exposed. Female connectors 8 are inserted into the hood 2 from the side of the connector 1 opposed to the direction in which it is inserted into the mounting hole W.
Although the male terminals 3 can be protected by the protecting cap 7, there is a possibility that something can strike against the locking arms 5 despite the provision of the protecting cap 7. Since each locking arm 5 has elasticity, it can return to its normal shape even when bending to an extent of its bending strength. However, each locking arm 5 cannot return to its normal shape when subjected to a force exceeding the limit of its bending strength, as shown by two-dot chain line in FIG. 10, which poses a problem.